package com.framework.core.text;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.crypto.*;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;


/**
 * AES加密解密工具
 *
 * @author fangls
 * @since hxzntech 1.0
 */
public class AESUtil {

	private static final Logger logger = LoggerFactory.getLogger(AESUtil.class);

    // KeyGenerator 提供对称密钥生成器的功能，支持各种算法
    private KeyGenerator keygen = null;
    // SecretKey 负责保存对称密钥
    private SecretKey deskey = null;
    // Cipher负责完成加密或解密工具
    private Cipher c = null;
    // 该字节数组负责保存加密的结果
    private byte[] cipherByte;

    public AESUtil(String key) throws NoSuchAlgorithmException,
            NoSuchPaddingException {
        //Security.addProvider(new com.sun.crypto.provider.SunJCE());
        // 实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
        keygen = KeyGenerator.getInstance("AES");
        SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
        secureRandom.setSeed(key.getBytes());
        keygen.init(128, secureRandom);
        // 生成密钥
        deskey = keygen.generateKey();
        // 生成Cipher对象,指定其支持的DES算法
        c = Cipher.getInstance("AES");
    }

    /**
     * 获取加密字符串
     *
     * @param key
     * @param msg
     * @return
     */
    @SuppressWarnings("static-access")
	public static String getEncryptAES(String key, String msg) {
        String encStr = "";
        try {
            AESUtil encAES = new AESUtil(key);
            byte[] encontent = encAES.Encrytor(msg);
            encStr = encAES.parseByte2HexStr(encontent);
        } catch (Exception e) {
            logger.error("getEncryptAES error", e);
        }
        return encStr;
    }

    /**
     * 获取揭秘字符串
     *
     * @param key
     * @param encStr
     * @return
     */
    public static String getDecryptAES(String key, String encStr) {
        String decStr = "";
        try {
            AESUtil decAES = new AESUtil(key);
            byte[] decontent = decAES.Decryptor(decAES.parseHexStr2Byte(encStr));
            decStr = new String(decontent);
        } catch (Exception e) {
            logger.error("getDecryptAES error", e);
        }
        return decStr;
    }

    /**
     * 校验密码是否正确，正确返回true，错误返回false
     *
     * @param key
     * @param ptex
     * @param secret
     * @return
     */
    public static boolean validPassWord(String key, String ptex, String secret) {
        String str = getDecryptAES(key, secret);
        if (str.equals(ptex)) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * 对字符串加密
     *
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public byte[] Encrytor(String str) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException {
        // 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
        c.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] src = str.getBytes();
        // 加密，结果保存进cipherByte
        cipherByte = c.doFinal(src);
        return cipherByte;
    }

    /**
     * 对字符串解密
     *
     * @param buff
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public byte[] Decryptor(byte[] buff) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException {
        // 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
        c.init(Cipher.DECRYPT_MODE, deskey);
        cipherByte = c.doFinal(buff);
        return cipherByte;
    }

    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * �?16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
                    16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

//    /**
//     * @param args
//     * @throws NoSuchPaddingException
//     * @throws NoSuchAlgorithmException
//     * @throws BadPaddingException
//     * @throws IllegalBlockSizeException
//     * @throws InvalidKeyException
//     */
//    public static void main(String[] args) throws Exception {
//        String key = "Flzx3qcY4yhljt";
//        String msg = "68D43C4D35E9150104F6C5D7B42639A1";
//        String encStr = AESUtil.getDecryptAES(key, msg);
//        System.out.println(encStr);
//    }
}
